The Long Cosmos

*The Long Cosmos* is the third book in the *Long Earth* series by Terry Pratchett and Stephen Baxter. It explores humanity’s continued expansion across an endless array of parallel Earths, created by a device called the "stepper." The story delves into themes of exploration, artificial intelligence, and the possibilities of existence beyond our universe. As humans and other beings navigate these infinite worlds, they face new challenges and moral questions about civilization, identity, and the nature of reality. The novel combines science fiction with thoughtful reflections on progress and the future of humanity in a multiverse of limitless worlds.